Beyond Bites: Differential Role of Fall Armyworm Oral Secretions and Saliva in Modulating Sorghum Defenses.

Flavonoids are major plant secondary metabolites that provide defense against several insect pests. Previously, it has been shown that sorghum (Sorghum bicolor) flavonoids are required for providing resistance to fall armyworm (FAW; Spodoptera frugiperda), which is an important chewing insect pest on several crops. We demonstrate here the role of FAW oral cues in modulating sorghum flavonoid defenses. While feeding, chewing insects release two kinds of oral cues: oral secretions (OS)/regurgitant and saliva. Our results indicate that FAW OS induced the expression of genes related to flavonoid biosynthesis and total flavonoids, thereby enhancing sorghum's defense against FAW larvae. Conversely, FAW saliva suppressed the flavonoid-based defenses and promoted FAW caterpillar growth, independent of the FAW salivary component, glucose oxidase (GOX). Thus, we infer that different oral cues in FAW may have contrasting roles in altering sorghum defenses. These findings expand our understanding of the precise modes of action of caterpillar oral cues in modulating plant defenses and help in designing novel pest management strategies against FAW in this vital cereal crop. [Formula: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Adaptive evolution of invasive fall armyworms to maize with potential involvement of Cytochrome P450 genes.

BACKGROUND: An invasion occurs when introduced species establish and maintain stable populations in areas outside of their native habitat. Adaptive evolution has been proposed to contribute to this process. The fall armyworm (Spodoptera frugiperda) is one of the major pest insects infesting maize in both invaded and native areas. The invasion of this species was reported from West Africa in 2016, followed by spreading across the Old World. We tested adaptive evolution to maize using 56 native samples from the USA and 59 invasive samples from Senegal, based on genomic and transcriptomic analyses. RESULTS: Principal component analysis revealed that the Senegalese population originated from corn strain. Three genetic loci were identified as targets of selective sweeps in the Senegalese population. These loci include four Cytochrome P450 genes (CYP321B1, CYP321B3, CYP321B4, and CYP337B5), as well as 12 genes of which the function is unclear. Transcriptomic analysis showed an overexpression of CYP321B1 and CYP321B3 genes in sfC samples compared to sfR samples. Additionally, these two genes were overexpressed when corn strain samples were exposed to maize. In larval feeding assays, the Senegalese population exhibited higher survival rates than a Floridan population across all four tested maize varieties. CONCLUSIONS: These results suggest that the analyzed Senegalese population experienced adaptive evolution involving loci containing CYP genes, potentially associated with an increase in the survival rates on maize. We argue that the invasive success of the fall armyworm is contributed by stabilizing selection to maize.

Region-Specific Variation in the Electrophysiological Responses of Spodoptera frugiperda (Lepidoptera: Noctuidae) to Synthetic Sex Pheromone Compounds.

The fall armyworm, Spodoptera frugiperda (J.E. Smith), is a global pest that feeds on > 350 plant species and causes major yield loses. Variation in the responses of S. frugiperda males to female sex pheromone compounds affects the detection, monitoring and management of the pest. We determined geographic variation in the responses of S. frugiperda males to four different doses of synthetic sex pheromone compounds using a gas chromatography-electroantennogram detector (GC-EAD). Furthermore, we disentangled regional populations into C- and R- mitotypes via molecular analysis of the cytochrome oxidase I gene, and measured their responses to the compounds. When comparing responses of males from Florida, Benin, Nigeria and Kenya, we found some regional differences in the responses of S. frugiperda males to the major compound, Z9-14:OAc and minor component Z9-12:OAc. However, we found no differences in male responses between the different African countries. All males showed significantly higher antennal responses to Z7-12:OAc than to E7-12:OAc. When comparing the mitotypes, we found that Florida R-type males showed higher responses to Z9-14:OAc, Z7-12:OAc and Z9-12:OAc than Benin R-type males, while C-type males from both regions responded equally to Z7-12:OAc. In addition, Florida R-type males showed higher responses to E7-12:OAc than Florida C-type males. Our study thus shows some differential physiological responses of S. frugiperda males towards the known sex pheromone compounds, including E7-12:OAc, but mostly in the different mitotypes. How these differences translate to field trap catches remains to be determined.

Heterologous expression of taxane genes confers resistance to fall armyworm in Nicotiana benthamiana.

KEY MESSAGE: Taxadiene synthase, taxadiene-5α-hydroxylase, and taxane 13α-hydroxylase genes were introduced into Nicotiana benthamiana, and the improved resistance to lepidoptera pest fall armyworm was reported. Fall armyworm (FAW) is a serious agricultural pest. Genetic engineering techniques have been used to create pest-resistant plant varieties for reducing pest damage. Paclitaxel is a diterpenoid natural metabolite with antineoplastic effects in medicine. However, the effects of taxanes on the growth and development of lepidoptera pests, such as the FAW, are unknown. Here, selected paclitaxel precursor biosynthesis pathway genes, taxadiene synthase, taxane 5α-hydroxylase, and taxane 13α-hydroxylase, were engineered in the heterologous host Nicotiana benthamiana plants. Bioassay experiments showed that the transgenic N. benthamiana plants displayed improved resistance to FAW infestation, with degeneration of gut tissues and induced expression of apoptosis-related genes. Cytotoxicity experiment showed that the paclitaxel precursor, 10-deacetylbaccatin III, is cytotoxic to Sf9 cells, causing cell cycle arrest at the G2/M phase and disorder of the cytoskeleton. Metabolome analysis showed that heterologous expression of taxane genes in N. benthamiana affected the digestive system, steroid hormone and purine metabolism pathways of FAW larvae. In summary, this study provides a candidate approach for FAW control.

Demographic analysis and biotic potential of Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) on pea.

The fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) is a highly destructive polyphagous pest that primarily damages maize. Maize is considered a most versatile crop for growing intercrops due to the wide row it needs. Maize-pea intercropping is preferred by small and marginal farmers worldwide due to various advantages including higher yield and improved economic benefits. However, the success of this intercropping system may be hampered if pea could sustain the FAW population. Thus, to clarify the fitness and potential effect of S. frugiperda on pea, we analysed the survival and development of S. frugiperda fed on pea leaves in the laboratory and constructed age-stage and two-sex life tables. Results showed that FAW successfully completed its life cycle when fed on pea and produced fertile offspring. The pre-adult duration was significantly higher on pea than maize. The net reproductive rate, intrinsic and finite rate of population increase on pea (135.06 offspring per individual, 0.12 offspring per individual per day and 1.13 times per day) were all significantly different from those on maize (417.64 offspring per individual, 0.19 offspring per individual per day and 1.21 times per day). The probability of survival of S. frugiperda at each stage was lower when fed on pea leaves than that of maize-fed larvae. Due to the overlapping growth periods of the maize and pea, S. frugiperda can easily proliferate throughout the year by shifting between adjacent crops. Thus, this study revealed the adaptability of S. frugiperda for pea and provides the foundation for further assessment of FAW risk to other inter-crops.

Synergistic mechanism of botanical pesticide camptothecin encapsulated in a nanocarrier against fall armyworm: Enhanced stability and amplified growth suppression.

Botanical pesticides are one of the most promising alternatives to synthetic insecticides for green pest management. However, their efficacies must be further improved to meet real needs. Here we designed a nanoscale camptothecin (CPT) encapsulated in a star polycation (SPc) and determined its bioactivity against a devastating agricultural pest, Spodoptera frugiperda. The self-assembly of CPT/SPc complex was mainly driven by hydrogen bonding and Van der Waals forces to decrease the particle size from 789 to 298 nm. With the help of SPc, the contact angle of CPT decreased from 116° to 92° on maize leaves, and its retention was increased from 5.53 to 11.97 mg/cm2. The stability of SPc-loaded CPT was also improved in an alkaline environment, which is beneficial for its acting in lepidopteran insect guts. The CPT/SPc complex had stronger larvicidal activity and ovicidal activity against S. frugiperda than CPT alone, led to more complex transcriptomic changes in larvae, and had obvious adverse impacts on the activities of two digestive enzymes. Our findings demonstrated that the encapsulation of CPT by SPc-based nanodelivery system enabled better insecticidal activities against S. frugiperda, which holds great promise for the development of more efficient and sustainable pest control strategies to meet the demands of modern crop protection.

Comparative toxicity and enzymatic detoxification responses in Spodoptera frugiperda (Lepidoptera: Noctuidae) to two insecticides.

The fall armyworm (FAW), Spodoptera frugiperda Smith (Lepidoptera: Noctuidae), poses a significant threat to food security, necessitating effective management strategies. While chemical control remains a primary approach, understanding the toxicity and detoxification mechanisms of different insecticides is crucial. In this study, we conducted leaf-dipping bioassays to assess the toxicity of quinalphos and beta-cypermethrin·emamectin benzoate (ß-cyp·EMB) on S. frugiperda larvae. Additionally, we assessed the response of alterations in CarE, GST, MFO, and AChE activities to sublethal concentrations of these insecticides over various treatment durations. Results indicated that ß-cyp·EMB exhibited higher toxicity than quinalphos in S. frugiperda. Interestingly, the highest activities of GST, CarE, MFO, and AChE were observed at 6 h exposure to LC10 and LC25 of ß-cyp·EMB, surpassing equivalent sublethal concentrations of quinalphos. Subsequently, GST and CarE activities exposure to ß-cyp·EMB steadily decreased, while MFO and AChE activities exposure to both insecticides was initially decreased then increased. Conversely, two sublethal concentrations of quinalphos notably enhanced GST activity across all exposure durations, with significantly higher than ß-cyp·EMB at 12-48 h. Similarly, CarE activity was also increased at various durations. Our research has exhibited significant alterations in enzyme activities exposure to both concentration and duration. Furthermore, Pearson correlation analysis showed significant correlations among these enzyme activities at different treatment durations. These findings contribute to a better understanding of detoxification mechanisms across different insecticides, providing valuable insights for the rational management of S. frugiperda populations.

Bulk segregant mapping and transcriptome analyses reveal the molecular mechanisms of spinetoram resistance in Spodoptera frugiperda.

The evolution of resistance to insecticides poses a significant threat to pest management programs. Understanding the molecular mechanisms underlying insecticide resistance is essential to design sustainable pest control and resistance management programs. The fall armyworm, Spodoptera frugiperda, is an important insect pest of many crops and has a remarkable ability to evolve resistance to insecticides. In this study, we employed bulk segregant analysis (BSA) combined with DNA and RNA sequencing to characterize the molecular basis of spinetoram resistance in S. frugiperda. Analysis of genomic data derived from spinetoram selected and unselected bulks and the spinetoram-resistant and susceptible parental strains led to the identification of a three-nucleotide deletion in the gene encoding the nicotinic acetylcholine receptor α6 subunit (nAChR α6). Transcriptome profiling identified the upregulation of few genes encoding detoxification enzymes associated with spinetoram resistance. Thus, spinetoram resistance in S. frugiperda appears to be mediated mainly by target site insensitivity with a minor role of detoxification enzymes. Our findings provide insight into the mechanisms underpinning resistance to spinetoram in S. frugiperda and will inform the development of strategies to control this highly damaging, globally distributed crop pest.

Knockout of the delta11-desaturase SfruDES1 disrupts sex pheromone biosynthesis, mating and oviposition in the fall armyworm, Spodoptera frugiperda.

Moth insects rely on sex pheromones for long distance attraction and searching for sex partners. The biosynthesis of moth sex pheromones involves the catalytic action of multiple enzymes, with desaturases playing a crucial role in the process of carbon chain desaturation. However, the specific desaturases involved in sex pheromone biosynthesis in fall armyworm (FAW), Spodoptera frugiperda, have not been clarified. In this study, a Δ11 desaturase (SfruDES1) gene in FAW was knocked out using the CRISPR/Cas9 genome editing system. A homozygous mutant of SfruDES1 was obtained through genetic crosses. The gas chromatography-mass spectrometry (GC-MS) analysis results showed that the three main sex pheromone components (Z7-12:Ac, Z9-14:Ac, and Z11-16:Ac) and the three minor components (Z9-14:Ald, E11-14:Ac and Z11-14:Ac) of FAW were not detected in homozygous mutant females compared to the wild type. Furthermore, behavioral assay demonstrated that the loss of SfruDES1 resulted in a significant reduction in the attractiveness of females to males, along with disruptions in mating behavior and oviposition. Additionally, in a heterologous expression system, recombinant SfruDES1 could introduce a cis double bond at the Δ11 position in palmitic acid, which resulted in the changes in components of the synthesized products. These findings suggest desaturase plays a key role in the biosynthesis of sex pheromones, and knockout of the SfruDES1 disrupts sex pheromone biosynthesis and mating behavior in FAW. The SfruDES1 could serve as tool to develop a control method for S. frugiperda.

Sphingomonas bacteria could serve as an early bioindicator for the development of chlorantraniliprole resistance in Spodoptera frugiperda.

The fall armyworm (Spodoptera frugiperda) was found to have invaded China in December 2018, and in just one year, crops in 26 provinces were heavily affected. Currently, the most effective method for emergency control of fulminant pests is to use of chemical pesticides. Recently, most fall armyworm populations in China were begining to exhibite low level resistance to chlorantraniliprole. At present, it is not possible to sensitively reflect the low level resistance of S. frugiperda by detecting target mutation and detoxification enzyme activity. In this study we found that 12 successive generations of screening with chlorantraniliprole caused S. frugiperda to develop low level resistance to this insecticide, and this phenotype was not attribute to genetic mutations in S. frugiperda, but rather to a marked increase in the relative amount of the symbiotic bacteria Sphingomonas. Using FISH and qPCR assays, we determined the amount of Sphingomonas in the gut of S. frugiperda and found Sphingomonas accumulation to be highest in the 3rd-instar larvae. Additionally, Sphingomonas was observed to provide a protective effect to against chlorantraniliprole stress to S. frugiperda. With the increase of the resistance to chlorantraniliprole, the abundance of bacteria also increased, we propose Sphingomonas monitoring could be adapted into an early warning index for the development of chlorantraniliprole resistance in S. frugiperda populations, such that timely measures can be taken to delay or prevent the widespread propagation of resistance to this highly useful agricultural chemical in S. frugiperda field populations.

Characterization of the mode of action of eCry1Gb.1Ig, a fall armyworm (Spodoptera frugiperda) active protein, with a novel site of action.

Insect pests cause immense agronomic losses worldwide. One of the most destructive of major crops is the Fall Armyworm (Spodoptera frugiperda, FAW). The ability to migrate long distances, a prodigious appetite, and a demonstrated ability to develop resistance to insecticides, make it a difficult target to control. Insecticidal proteins, for example those produced by the bacterium Bacillus thuringiensis, are among the safest and most effective insect control agents. Genetically modified (GM) crops expressing such proteins are a key part of a successful integrated pest management (IPM) program for FAW. However, due to the development of populations resistant to commercialized GM products, new GM traits are desperately needed. Herein, we describe a further characterization of the newly engineered trait protein eCry1Gb.1Ig. Similar to other well characterized Cry proteins, eCry1Gb.1Ig is shown to bind FAW midgut cells and induce cell-death. Binding competition assays using trait proteins from other FAW-active events show a lack of competition when binding FAW brush border membrane vesicles (BBMVs) and when utilizing non-pore-forming versions as competitors in in vivo bioassays. Similarly, insect cell lines expressing SfABCC2 and SfABCC3 (well characterized receptors of existing commercial Cry proteins) are insensitive to eCry1Gb.1Ig. These findings are consistent with results from our previous work showing that eCry1Gb.1Ig is effective in controlling insects with resistance to existing traits. This underscores the value of eCry1Gb.1Ig as a new GM trait protein with a unique site-of-action and its potential positive impact to global food production.

Trade-offs between the accumulation of cuticular wax and jasmonic acid-mediated herbivory resistance in maize.

Plants have evolved complex physical and chemical defense systems that allow them to withstand herbivory infestation. Composed of a complex mixture of very-long-chain fatty acids (VLCFAs) and their derivatives, cuticular wax constitutes the first physical line of defense against herbivores. Here, we report the function of Glossy 8 (ZmGL8), which encodes a 3-ketoacyl reductase belonging to the fatty acid elongase complex, in orchestrating wax production and jasmonic acid (JA)-mediated defenses against herbivores in maize (Zea mays). The mutation of GL8 enhanced chemical defenses by activating the JA-dependent pathway. We observed a trade-off between wax accumulation and JA levels across maize glossy mutants and 24 globally collected maize inbred lines. In addition, we demonstrated that mutants defective in cuticular wax biosynthesis in Arabidopsis thaliana and maize exhibit enhanced chemical defenses. Comprehensive transcriptomic and lipidomic analyses indicated that the gl8 mutant confers chemical resistance to herbivores by remodeling VLCFA-related lipid metabolism and subsequent JA biosynthesis and signaling. These results suggest that VLCFA-related lipid metabolism has a critical role in regulating the trade-offs between cuticular wax and JA-mediated chemical defenses.

CRISPR/Cas9-mediated genome editing technique to control fall armyworm (Spodoptera frugiperda) in crop plants with special reference to maize.

Fall Armyworm imposes a major risk to agricultural losses. Insecticides have historically been used to manage its infestations, but it eventually becomes resistant to them. To combat the pest, a more recent strategy based on the use of transgenic maize that expresses Bt proteins such as Cry1F from the bacteria has been used. Nonetheless, there have been numerous reports of Cry1F maize resistance in FAW populations. Nowadays, the more effective and less time-consuming genome editing method known as CRISPR/Cas9 technology has gradually supplanted these various breeding techniques. This method successfully edits the genomes of various insects, including Spodoptera frugiperda. On the other hand, this new technique can change an insect's DNA to overcome its tolerance to specific insecticides or to generate a gene drive. The production of plant cultivars resistant to fall armyworms holds great potential for the sustainable management of this pest, given the swift advancement of CRISPR/Cas9 technology and its varied uses. Thus, this review article discussed and critically assessed the use of CRISPR/Cas9 genome-editing technology in long-term fall armyworm pest management. However, this review study focuses primarily on the mechanism of the CRISPR-Cas9 system in both crop plants and insects for FAW management.

Genetic analyses and detection of point mutations in the acetylcholinesterase-1 gene associated with organophosphate insecticide resistance in fall armyworm (Spodoptera frugiperda) populations from Uganda.

BACKGROUND: The fall armyworm (FAW), Spodoptera frugiperda; J.E. Smith (Lepidoptera: Noctuidae), is now an economically important pest that causes huge losses to maize productivity in sub-Saharan Africa. Variations in sub-population genetics and the processes of rapid adaptation underpinning the invasion remain unclear. For this, the genetic identity and diversity of FAW populations in Uganda were revealed by sequencing 87 samples (collected across the country). Based on the partial mitochondrial cytochrome oxidase I (COI) gene polymorphisms, we further examined the mitochondrial haplotype configuration and compared the FAW in Uganda with sequences from other parts of the world. The molecular target for organophosphate and carbamate resistance, acetylcholinesterase, was also investigated. RESULTS: Analysis of the partial COI gene sequences showed the presence of both rice (predominant) and corn strain haplotypes, with a haplotype diversity of 0.382. Based on the COI marker, pairwise difference distribution analyses, and neutrality tests, showed that the FAW populations in Uganda and the rest of Africa are evolving neutrally, but those in America and Asia are undergoing expansion. Our findings support observations that invasive FAW populations throughout the rest of Africa and Asia share a common origin. Sequencing of the S. frugiperda ace-1 gene revealed four amino acid substitutions, two of which (A201S and F290V) were previously shown to confer organophosphate resistance in both S. frugiperda and several other insect species. The other two previously reported new variations in positions g-396 and g-768, are presumed to be related to the development of insecticide resistance. CONCLUSIONS: This research has increased our knowledge of the genetics of FAW in Uganda, which is critical for pest surveillance and the detection of resistance. However, due to the low gene polymorphism of COI, more evolutionary studies incorporating the Spodoptera frugiperda whole-genome sequence are required to precisely understand the FAW population dynamics, introduction paths, origin, and subsequent spread.

Evidence of population expansion and insecticide resistance mechanism in invasive fall armyworm (Spodoptera frugiperda).

BACKGROUND: The invasive and calamitous polyphagous pest Spodoptera frugiperda or commonly known as fall armyworm (FAW) poses serious menace to the global agricultural production. Owing to the revamped invasion of FAW in 2018 in India, present study was undertaken for precise assessment of its genetic identity and pesticide resistance to aid in pest-management strategies. RESULTS: To evaluate the diversity in FAW population across Eastern India, mitochondrial COI sequences were used which revealed a low nucleotide diversity. Analysis of molecular variance indicated significant genetic variation between four global geographical FAW populations with lowest differentiation between India and Africa suggesting a present-day and shared origin of FAW. The study demonstrated existence of two different strains ('R' strain and 'C' strain) based on COI gene marker. However, discrepancies between COI marker and host plant association of FAW was observed. Characterization of Tpi gene revealed abundance of TpiCa1a followed by TpiCa2b and TpiR1a strains respectively. The FAW population showed higher susceptibility towards chlorantraniliprole and spinetoram than cypermethrin. Insecticide resistance genes depicted marked upregulation although with lot of variance. Chlorantraniliprole resistance ratio (RR) exhibited significant correlation with 1950 (Glutathione S-transferase, GST), 9131 (Cytochrome P450, CYP) and 9360 (CYP) genes, while spinetoram and cypermethrin RR was found to correlate with 1950 (GST) and 9360 (CYP) genes. CONCLUSION: This study manifests Indian subcontinent as the potential new hotspot for the growth and distribution of FAW population that can be effectively controlled using chlorantraniliprole and spinetoram. This study also adds novel significant information on FAW population across Eastern India for developing a comprehensive pest management approach for S. frugiperda.

Sorghum defense responses to sequential attack by insect herbivores of different feeding guilds.

MAIN CONCLUSION: Insect herbivores of different feeding guilds induced sorghum defenses through differential mechanisms, regardless of the order of herbivore arrival on sorghum plants. Sorghum, one of the world's most important cereal crops, suffers severe yield losses due to attack by insects of different feeding guilds. In most instances, the emergence of these pests are not secluded incidents and are followed by another or can also co-infest host plants. Sugarcane aphid (SCA) and fall armyworm (FAW) are the two most important destructive pests of sorghum, which belongs to sap-sucking and chewing feeding guilds, respectively. While the order of the herbivore arriving on the plants has been found to alter the defense response to subsequent herbivores, this is seldom studied with herbivores from different feeding guilds. In this study, we investigated the effects of sequential herbivory of FAW and SCA on sorghum defense responses and their underlying mechanism(s). Sequential feeding on the sorghum RTx430 genotype by either FAW primed-SCA or SCA primed-FAW were monitored to unravel the mechanisms underlying defense priming, and its mode of action. Regardless of the order of herbivore arrival on sorghum RTx430 plants, significant defense induction was observed in the primed state compared to the non-primed condition, irrespective of their feeding guild. Additionally, gene expression and secondary metabolite analysis revealed differential modulation of the phenylpropanoid pathway upon insect attack by different feeding guilds. Our findings suggest that priming in sorghum plants upon sequential herbivory induces defense by the accumulation of the total flavonoids and lignin/salicylic acid in FAW primed-SCA and SCA primed-FAW interaction, respectively.

Global genomic signature reveals the evolution of fall armyworm in the Eastern hemisphere.

The major plant pest fall armyworm (FAW), Spodoptera frugiperda, is native to the Americas and has colonized Africa and Asia within the Eastern hemisphere since 2016, causing severe damage to multiple agricultural crop species. However, the genetic origin of these invasive populations requires more in-depth exploration. We analysed genetic variation across the genomes of 280 FAW individuals from both the Eastern hemisphere and the Americas. The global range-wide genetic structure of FAW shows that the FAW in America has experienced deep differentiation, largely consistent with the Z-chromosomal Tpi haplotypes commonly used to differentiate 'corn-strain' and 'rice-strain' populations. The invasive populations from Africa and Asia are different from the American ones and have a relatively homogeneous population structure, consistent with the common origin and recent spreading from Africa to Asia. Our analyses suggest that north- and central American 'corn-strain' FAW are the most likely sources of the invasion into the Eastern hemisphere. Furthermore, evidence based on genomic, transcriptomic and mitochondrial haplotype network analyses indicates an earlier, independent introduction of FAW into Africa, with subsequent migration into the recent invasive population.

Efficacy of drought-tolerant and insect-protected transgenic TELA® maize traits in Nigeria.

Assessment of efficacy of drought tolerance (DT) and insect protection (Bt) genes in maize genotypes is invaluable for commercialization and production of transgenic maize in Nigeria. Seven maize hybrids, known as TELA® maize, with stacked events of Bt insect protection (MON89034) and drought tolerance (MON87460; DroughtGard®) and their respective non-GM versions (isohybrids) developed through the TELA Maize Project were evaluated in confined field trial site at Zaria in 2020 and 2021. The objective was to assess the efficacy of stacked DT and Bt genes to seek deregulation and commercialization of both traits in Nigeria. Significant (P < 0.05-0.01) differences were observed among genotypes (G), environments (E) and genotype × environment interaction (GEI) for grain yield and most other traits under stem borer (moth species) and fall armyworm infested, drought stress, and optimum-moisture conditions, except E and GEI under drought. TELA® GM hybrids with Bt MON89034 had 19% higher yield than their non-GM isogenic versions, and 40% higher yield than the commercial checks under the target pests infestation. The foliar damage score of all the TELA® GM genotypes was ≤ 2 relative to their non-GM isogenic versions which scored ≥ 4, indicating the effectiveness of the Bt MON89034 gene in conferring resistance against stem borer and fall armyworm. Under moderate drought, pairwise comparison showed TELA® GM Hybrid 1-1 and Hybrid 2-1 had 12.4-20.4% higher (P < 0.01) yield than their isogenic versions. Under optimum-moisture condition with pests controlled, the TELA® GM and their isogenic hybrids were similar, but both had 32% higher yield than the commercial checks. Adoption of TELA® GM technology by farmers as adaptation strategy to cope with climate change, will ensure sustainability of maize production and productivity in Nigeria.

In the wind: Invasive species travel along predictable atmospheric pathways.

Invasive species such as insects, pathogens, and weeds reaching new environments by traveling with the wind, represent unquantified and difficult-to-manage biosecurity threats to human, animal, and plant health in managed and natural ecosystems. Despite the importance of these invasion events, their complexity is reflected by the lack of tools to predict them. Here, we provide the first known evidence showing that the long-distance aerial dispersal of invasive insects and wildfire smoke, a potential carrier of invasive species, is driven by atmospheric pathways known as Lagrangian coherent structures (LCS). An aerobiological modeling system combining LCS modeling with species biology and atmospheric survival has the potential to transform the understanding and prediction of atmospheric invasions. The proposed modeling system run in forecast or hindcast modes can inform high-risk invasion events and invasion source locations, making it possible to locate them early, improving the chances of eradication success.

Comparative Genomics of Pesticide-Degrading Enterococcus Symbionts of Spodoptera frugiperda (Lepidoptera: Noctuidae) Leads to the Identification of Two New Species and the Reappraisal of Insect-Associated Enterococcus Species.

Enterococcus species have been described as core members of the microbial community of Spodoptera frugiperda (Lepidoptera: Noctuidae) and have been previously reported as insecticide degrading agents. This study aimed to investigate the molecular composition of these microbial symbionts of S. frugiperda to better understand their association with the host and their potential for insecticide metabolization. Through phenotypic assays and comparative genomic analyses of several pesticide-degrading Enterococcus isolated from the gut of S. frugiperda larvae, we identified two new species: Enterococcus entomosocium n. sp. and Enterococcus spodopteracolus n. sp. Their identities as new species were confirmed by whole genome alignment, utilizing cut-offs of 95-96% for the average nucleotide identity (ANI) and 70% for the digital DNA: DNA hybridization (dDDH) values. The systematic positioning of these new species within the genus Enterococcus was resolved using genome-based analysis, revealing Enterococcus casseliflavus as a sister group of E. entomosocium n. sp., and Enterococcus mundtii as a sister group of E. spodopteracolus n. sp. Comparative genomic analyses of several isolates of E. entomosocium n. sp. and E. spodopteracolus n. sp. provided a better assessment of the interactions established in the symbiotic association with S. frugiperda and led to the discovery of misidentified new species of Enterococcus associated with insects. Our analyses indicated that the potential of E. entomosocium n. sp. and E. spodopteracolus n. sp. to metabolize different pesticides arises from molecular mechanisms that result in rapid evolution of new phenotypes in response to environmental stressors, in this case, the pesticides their host insect is exposed to.